Nippon Telegraph and Telephone Corporation

Mika Ishizuka

Hiroshi Inoue

Hiroyuki Tanaka

Seisho Yasukawa

Yasuharu Kaneko

Kojun Koshiji

Eiji Kobayashi

Shinichi Doi

Keiichiro Kashiwagi

Takuma Tsubaki

Saburo Seto

Ryosuke Kurebayashi

Miki Kitabata

A topology design device for an optical transmission network includes a memory; and a processor to determine a bypass target area as an area to which a bypass route is to be added in the network, the area indicating a region surrounded by nodes and edges, based on an area demand, namely a total value of a demand for communication to be performed via an edge, by referencing a topology management database storing information regarding nodes, edges, and areas in the network, and a demand management database storing demands in the network; and exclude a node from nodes constituting the bypass target area and determining a bypass route from the nodes from which the node has been excluded, based on a node demand, namely a total value of a demand for which each node serves as a start or end point of the demand, by referencing the databases.

Topology design apparatus, topology design method and program

A local wavelength defragmentation apparatus performs wavelength defragmentation for at least one wavelength path passing through a target link in an optical transmission network. The local wavelength defragmentation apparatus includes a reallocation rank determination unit configured to calculate a remaining time from a present time to an abolition timing for each of the at least one wavelength path and determine rank for wavelength reallocation of the at least one wavelength path based on the remaining time; and a reallocation number determination unit configured to calculate utilization of at least one reallocatable wavelength number for each of the at least one wavelength path according to the rank, and determine a wavelength so that a wavelength of the wavelength number having the highest utilization is reallocated.

Local wavelength defrag apparatus, local wavelength defrag method and program

A demand prediction apparatus allows for a prediction with a variation in terms of demand by acquiring, out of changes in demand in a first time period, changes in the demand in a second time period which is a part of the first time period acquiring changes in the demand in third time periods, which is a plurality of time periods excluding the second time period within the first time period, for each of the third time periods having different lengths, identifying, for combinations of a plurality of trend patterns and the third time periods, parameters of the corresponding plurality of trend patterns such that a value of a trend pattern of the plurality of trend patterns is equal to the demand at a certain time point in the first time period, evaluating suitability with the changes in the demand in the second time period for each of the plurality of trend patterns for each of the combinations in which a parameter of the parameters is identified, and selecting one or more trend patterns from among the plurality of trend patterns for each of the combinations based on evaluation results.

Demand prediction apparatus, demand prediction method and program for predicting a demand of a path on a network using selected trend patterns

A computer executes a first determination procedure determining a first link which at least partially overlaps a disaster area representing a range reached by an influence of a predetermined disaster, among links constituting a network, a second determination procedure determining a second link which at least partially overlaps a road area representing a range of a road width of a predetermined road used to recover from the disaster, among the links constituting the network, a route search procedure searching for a plurality of routes from a start point node to an end point node constituting the network, a grouping procedure grouping the plurality of routes searched for by the route search procedure into groups depending on a first parameter value that is based on the first link included in the routes, a computing procedure computing, for each of the plurality of routes searched for by the route search procedure, a second parameter value that is based on the first link and the second link included in the routes, and a selecting procedure selecting a predetermined number of routes among one or more routes grouped into the same group on the basis of the second parameter value computed by the computing procedure for each of the groups grouped by the grouping procedure.

Route calculation method, route calculation apparatus and program

A Web browser capable of providing an equivalent quality of user experience to a user even with respect to access of devices differing in processing performance. The web browsing system comprises a Web browser function which is divided between a browsing client unit and a browsing server unit, wherein the browsing client unit notifies a content input to the user terminal to the browsing server unit and displays a Web page on a user terminal by using information supplied from the browsing server unit, and wherein the browsing server unit supplies information necessary for displaying the Web page to the user terminal to the browsing client unit according to the content input to the user terminal notified from the browsing client unit.

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Tokyo, Japan

Mika Ishizuka